I want to power my RPi with a lithium ion battery. The RPi will be powering some devices which require constant voltage to power them.
If I use a battery as supply for the RPi (which changes as it depletes), will the 3.3 or 5V pins still output a constant voltage?
I saw this post here: Does the Raspberry Pi 3 regulate the voltage on its 5V pins?
which seems to rule this out for the 5V pin, but I wasn't clear on the 3.3V pin, can anyone advise?
This post: https://raspberrypise.tumblr.com/post/144555785379/exploring-the-33v-power-rail
appears to confirm the constant 3.3V output, but would appreciate confirmation by someone with more experience